diff --git a/common.mk b/common.mk
index 9d58fa21..9b5ef0ea 100644
--- a/common.mk
+++ b/common.mk
@@ -11,7 +11,7 @@ SRC +=	$(COMMON_DIR)/host.c \
 	$(COMMON_DIR)/print.c \
 	$(COMMON_DIR)/bootloader.c \
 	$(COMMON_DIR)/suspend.c \
-	$(COMMON_DIR)/xprintf.S \
+	$(COMMON_DIR)/avr/xprintf.S \
 	$(COMMON_DIR)/util.c
 
 
diff --git a/common/action.c b/common/action.c
index fddb97c5..94498fe6 100644
--- a/common/action.c
+++ b/common/action.c
@@ -499,7 +499,7 @@ void clear_keyboard_but_mods(void)
 #endif
 }
 
-bool is_tap_key(key_t key)
+bool is_tap_key(keypos_t key)
 {
     action_t action = layer_switch_get_action(key);
 
diff --git a/common/action.h b/common/action.h
index 077711c2..8a4736d7 100644
--- a/common/action.h
+++ b/common/action.h
@@ -25,6 +25,10 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include "action_macro.h"
 
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /* tapping count and state */
 typedef struct {
     bool    interrupted :1;
@@ -42,12 +46,11 @@ typedef struct {
 #endif
 } keyrecord_t;
 
-
 /* Execute action per keyevent */
 void action_exec(keyevent_t event);
 
 /* action for key */
-action_t action_for_key(uint8_t layer, key_t key);
+action_t action_for_key(uint8_t layer, keypos_t key);
 
 /* macro */
 const macro_t *action_get_macro(keyrecord_t *record, uint8_t id, uint8_t opt);
@@ -65,11 +68,15 @@ void unregister_mods(uint8_t mods);
 void clear_keyboard(void);
 void clear_keyboard_but_mods(void);
 void layer_switch(uint8_t new_layer);
-bool is_tap_key(key_t key);
+bool is_tap_key(keypos_t key);
 
 /* debug */
 void debug_event(keyevent_t event);
 void debug_record(keyrecord_t record);
 void debug_action(action_t action);
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif  /* ACTION_H */
diff --git a/common/action_layer.c b/common/action_layer.c
index 526e24d5..c535615f 100644
--- a/common/action_layer.c
+++ b/common/action_layer.c
@@ -112,7 +112,7 @@ void layer_debug(void)
 
 
 
-action_t layer_switch_get_action(key_t key)
+action_t layer_switch_get_action(keypos_t key)
 {
     action_t action;
     action.code = ACTION_TRANSPARENT;
diff --git a/common/action_layer.h b/common/action_layer.h
index 034e0002..b6da353c 100644
--- a/common/action_layer.h
+++ b/common/action_layer.h
@@ -72,6 +72,6 @@ void layer_xor(uint32_t state);
 
 
 /* return action depending on current layer status */
-action_t layer_switch_get_action(key_t key);
+action_t layer_switch_get_action(keypos_t key);
 
 #endif
diff --git a/common/action_macro.c b/common/action_macro.c
index d85aee37..ba93fc8b 100644
--- a/common/action_macro.c
+++ b/common/action_macro.c
@@ -14,10 +14,10 @@ GNU General Public License for more details.
 You should have received a copy of the GNU General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
-#include <util/delay.h>
 #include "action.h"
 #include "action_util.h"
 #include "action_macro.h"
+#include "wait.h"
 
 #ifdef DEBUG_ACTION
 #include "debug.h"
@@ -28,7 +28,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 #ifndef NO_ACTION_MACRO
 
-#define MACRO_READ()  (macro = pgm_read_byte(macro_p++))
+#define MACRO_READ()  (macro = MACRO_GET(macro_p++))
 void action_macro_play(const macro_t *macro_p)
 {
     macro_t macro = END;
@@ -58,7 +58,7 @@ void action_macro_play(const macro_t *macro_p)
             case WAIT:
                 MACRO_READ();
                 dprintf("WAIT(%u)\n", macro);
-                { uint8_t ms = macro; while (ms--) _delay_ms(1); }
+                { uint8_t ms = macro; while (ms--) wait_ms(1); }
                 break;
             case INTERVAL:
                 interval = MACRO_READ();
@@ -77,7 +77,7 @@ void action_macro_play(const macro_t *macro_p)
                 return;
         }
         // interval
-        { uint8_t ms = interval; while (ms--) _delay_ms(1); }
+        { uint8_t ms = interval; while (ms--) wait_ms(1); }
     }
 }
 #endif
diff --git a/common/action_macro.h b/common/action_macro.h
index 62182630..aedc32ec 100644
--- a/common/action_macro.h
+++ b/common/action_macro.h
@@ -17,12 +17,12 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #ifndef ACTION_MACRO_H
 #define ACTION_MACRO_H
 #include <stdint.h>
-#include <avr/pgmspace.h>
+#include "progmem.h"
 
 
-#define MACRO_NONE  0
-#define MACRO(...) ({ static const macro_t __m[] PROGMEM = { __VA_ARGS__ }; &__m[0]; })
-
+#define MACRO_NONE      0
+#define MACRO(...)      ({ static const macro_t __m[] PROGMEM = { __VA_ARGS__ }; &__m[0]; })
+#define MACRO_GET(p)    pgm_read_byte(p)
 
 typedef uint8_t macro_t;
 
diff --git a/common/action_util.c b/common/action_util.c
index 5f44b381..dbee630d 100644
--- a/common/action_util.c
+++ b/common/action_util.c
@@ -31,8 +31,8 @@ static uint8_t real_mods = 0;
 static uint8_t weak_mods = 0;
 
 #ifdef USB_6KRO_ENABLE
-#define RO_ADD(a, b) ((a + b) % REPORT_KEYS)
-#define RO_SUB(a, b) ((a - b + REPORT_KEYS) % REPORT_KEYS)
+#define RO_ADD(a, b) ((a + b) % KEYBOARD_REPORT_KEYS)
+#define RO_SUB(a, b) ((a - b + KEYBOARD_REPORT_KEYS) % KEYBOARD_REPORT_KEYS)
 #define RO_INC(a) RO_ADD(a, 1)
 #define RO_DEC(a) RO_SUB(a, 1)
 static int8_t cb_head = 0;
@@ -98,7 +98,7 @@ void del_key(uint8_t key)
 void clear_keys(void)
 {
     // not clear mods
-    for (int8_t i = 1; i < REPORT_SIZE; i++) {
+    for (int8_t i = 1; i < KEYBOARD_REPORT_SIZE; i++) {
         keyboard_report->raw[i] = 0;
     }
 }
@@ -145,7 +145,7 @@ void clear_oneshot_mods(void)
 uint8_t has_anykey(void)
 {
     uint8_t cnt = 0;
-    for (uint8_t i = 1; i < REPORT_SIZE; i++) {
+    for (uint8_t i = 1; i < KEYBOARD_REPORT_SIZE; i++) {
         if (keyboard_report->raw[i])
             cnt++;
     }
@@ -162,7 +162,7 @@ uint8_t get_first_key(void)
 #ifdef NKRO_ENABLE
     if (keyboard_nkro) {
         uint8_t i = 0;
-        for (; i < REPORT_BITS && !keyboard_report->nkro.bits[i]; i++)
+        for (; i < KEYBOARD_REPORT_BITS && !keyboard_report->nkro.bits[i]; i++)
             ;
         return i<<3 | biton(keyboard_report->nkro.bits[i]);
     }
@@ -234,7 +234,7 @@ static inline void add_key_byte(uint8_t code)
 #else
     int8_t i = 0;
     int8_t empty = -1;
-    for (; i < REPORT_KEYS; i++) {
+    for (; i < KEYBOARD_REPORT_KEYS; i++) {
         if (keyboard_report->keys[i] == code) {
             break;
         }
@@ -242,7 +242,7 @@ static inline void add_key_byte(uint8_t code)
             empty = i;
         }
     }
-    if (i == REPORT_KEYS) {
+    if (i == KEYBOARD_REPORT_KEYS) {
         if (empty != -1) {
             keyboard_report->keys[empty] = code;
         }
@@ -278,7 +278,7 @@ static inline void del_key_byte(uint8_t code)
         } while (i != cb_tail);
     }
 #else
-    for (uint8_t i = 0; i < REPORT_KEYS; i++) {
+    for (uint8_t i = 0; i < KEYBOARD_REPORT_KEYS; i++) {
         if (keyboard_report->keys[i] == code) {
             keyboard_report->keys[i] = 0;
         }
@@ -289,7 +289,7 @@ static inline void del_key_byte(uint8_t code)
 #ifdef NKRO_ENABLE
 static inline void add_key_bit(uint8_t code)
 {
-    if ((code>>3) < REPORT_BITS) {
+    if ((code>>3) < KEYBOARD_REPORT_BITS) {
         keyboard_report->nkro.bits[code>>3] |= 1<<(code&7);
     } else {
         dprintf("add_key_bit: can't add: %02X\n", code);
@@ -298,7 +298,7 @@ static inline void add_key_bit(uint8_t code)
 
 static inline void del_key_bit(uint8_t code)
 {
-    if ((code>>3) < REPORT_BITS) {
+    if ((code>>3) < KEYBOARD_REPORT_BITS) {
         keyboard_report->nkro.bits[code>>3] &= ~(1<<(code&7));
     } else {
         dprintf("del_key_bit: can't del: %02X\n", code);
diff --git a/common/action_util.h b/common/action_util.h
index f9d3161a..a955638b 100644
--- a/common/action_util.h
+++ b/common/action_util.h
@@ -20,6 +20,10 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include <stdint.h>
 #include "report.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 extern report_keyboard_t *keyboard_report;
 
 void send_keyboard_report(void);
@@ -54,4 +58,9 @@ void oneshot_disable(void);
 uint8_t has_anykey(void);
 uint8_t has_anymod(void);
 uint8_t get_first_key(void);
+
+#ifdef __cplusplus
+}
+#endif
+
 #endif
diff --git a/common/bootmagic.c b/common/bootmagic.c
index 642d5fac..b002a585 100644
--- a/common/bootmagic.c
+++ b/common/bootmagic.c
@@ -111,7 +111,7 @@ static bool scan_keycode(uint8_t keycode)
         matrix_row_t matrix_row = matrix_get_row(r);
         for (uint8_t c = 0; c < MATRIX_COLS; c++) {
             if (matrix_row & ((matrix_row_t)1<<c)) {
-                if (keycode == keymap_key_to_keycode(0, (key_t){ .row = r, .col = c })) {
+                if (keycode == keymap_key_to_keycode(0, (keypos_t){ .row = r, .col = c })) {
                     return true;
                 }
             }
diff --git a/common/host.c b/common/host.c
index 2e56971b..e9b79167 100644
--- a/common/host.c
+++ b/common/host.c
@@ -16,7 +16,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
 #include <stdint.h>
-#include <avr/interrupt.h>
+//#include <avr/interrupt.h>
 #include "keycode.h"
 #include "host.h"
 #include "util.h"
@@ -55,7 +55,7 @@ void host_keyboard_send(report_keyboard_t *report)
 
     if (debug_keyboard) {
         dprint("keyboard_report: ");
-        for (uint8_t i = 0; i < REPORT_SIZE; i++) {
+        for (uint8_t i = 0; i < KEYBOARD_REPORT_SIZE; i++) {
             dprintf("%02X ", report->raw[i]);
         }
         dprint("\n");
diff --git a/common/keyboard.c b/common/keyboard.c
index 2b66f20a..b71d5bf1 100644
--- a/common/keyboard.c
+++ b/common/keyboard.c
@@ -100,7 +100,7 @@ void keyboard_task(void)
             for (uint8_t c = 0; c < MATRIX_COLS; c++) {
                 if (matrix_change & ((matrix_row_t)1<<c)) {
                     action_exec((keyevent_t){
-                        .key = (key_t){ .row = r, .col = c },
+                        .key = (keypos_t){ .row = r, .col = c },
                         .pressed = (matrix_row & ((matrix_row_t)1<<c)),
                         .time = (timer_read() | 1) /* time should not be 0 */
                     });
diff --git a/common/keyboard.h b/common/keyboard.h
index d1a92242..60f8a89d 100644
--- a/common/keyboard.h
+++ b/common/keyboard.h
@@ -30,16 +30,16 @@ extern "C" {
 typedef struct {
     uint8_t col;
     uint8_t row;
-} key_t;
+} keypos_t;
 
 /* key event */
 typedef struct {
-    key_t    key;
+    keypos_t key;
     bool     pressed;
     uint16_t time;
 } keyevent_t;
 
-/* equivalent test of key_t */
+/* equivalent test of keypos_t */
 #define KEYEQ(keya, keyb)       ((keya).row == (keyb).row && (keya).col == (keyb).col)
 
 /* Rules for No Event:
@@ -52,7 +52,7 @@ static inline bool IS_RELEASED(keyevent_t event) { return (!IS_NOEVENT(event) &&
 
 /* Tick event */
 #define TICK                    (keyevent_t){           \
-    .key = (key_t){ .row = 255, .col = 255 },           \
+    .key = (keypos_t){ .row = 255, .col = 255 },           \
     .pressed = false,                                   \
     .time = (timer_read() | 1)                          \
 }
diff --git a/common/keymap.c b/common/keymap.c
index bfb8ffac..0df2e2ed 100644
--- a/common/keymap.c
+++ b/common/keymap.c
@@ -28,7 +28,7 @@ static action_t keycode_to_action(uint8_t keycode);
 
 
 /* converts key to action */
-action_t action_for_key(uint8_t layer, key_t key)
+action_t action_for_key(uint8_t layer, keypos_t key)
 {
     uint8_t keycode = keymap_key_to_keycode(layer, key);
     switch (keycode) {
@@ -156,7 +156,7 @@ static action_t keycode_to_action(uint8_t keycode)
  *      Consider using new keymap API instead.
  */
 __attribute__ ((weak))
-uint8_t keymap_key_to_keycode(uint8_t layer, key_t key)
+uint8_t keymap_key_to_keycode(uint8_t layer, keypos_t key)
 {
     return keymap_get_keycode(layer, key.row, key.col);
 }
diff --git a/common/keymap.h b/common/keymap.h
index 4c3019a3..e1a6f992 100644
--- a/common/keymap.h
+++ b/common/keymap.h
@@ -43,7 +43,7 @@ keymap_config_t keymap_config;
 
 
 /* translates key to keycode */
-uint8_t keymap_key_to_keycode(uint8_t layer, key_t key);
+uint8_t keymap_key_to_keycode(uint8_t layer, keypos_t key);
 
 /* translates Fn keycode to action */
 action_t keymap_fn_to_action(uint8_t keycode);
diff --git a/common/print.h b/common/print.h
index 4001bcf1..a8dbbc02 100644
--- a/common/print.h
+++ b/common/print.h
@@ -37,7 +37,7 @@
 
 #if defined(__AVR__)
 
-#include "xprintf.h"
+#include "avr/xprintf.h"
 
 
 // TODO: avoid collision with arduino/Print.h
diff --git a/common/report.h b/common/report.h
index 71543cc2..62190469 100644
--- a/common/report.h
+++ b/common/report.h
@@ -74,19 +74,19 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 /* key report size(NKRO or boot mode) */
 #if defined(PROTOCOL_PJRC) && defined(NKRO_ENABLE)
 #   include "usb.h"
-#   define REPORT_SIZE KBD2_SIZE
-#   define REPORT_KEYS (KBD2_SIZE - 2)
-#   define REPORT_BITS (KBD2_SIZE - 1)
+#   define KEYBOARD_REPORT_SIZE KBD2_SIZE
+#   define KEYBOARD_REPORT_KEYS (KBD2_SIZE - 2)
+#   define KEYBOARD_REPORT_BITS (KBD2_SIZE - 1)
 
 #elif defined(PROTOCOL_LUFA) && defined(NKRO_ENABLE)
 #   include "protocol/lufa/descriptor.h"
-#   define REPORT_SIZE NKRO_EPSIZE
-#   define REPORT_KEYS (NKRO_EPSIZE - 2)
-#   define REPORT_BITS (NKRO_EPSIZE - 1)
+#   define KEYBOARD_REPORT_SIZE NKRO_EPSIZE
+#   define KEYBOARD_REPORT_KEYS (NKRO_EPSIZE - 2)
+#   define KEYBOARD_REPORT_BITS (NKRO_EPSIZE - 1)
 
 #else
-#   define REPORT_SIZE 8
-#   define REPORT_KEYS 6
+#   define KEYBOARD_REPORT_SIZE 8
+#   define KEYBOARD_REPORT_KEYS 6
 #endif
 
 
@@ -115,16 +115,16 @@ extern "C" {
  *
  */
 typedef union {
-    uint8_t raw[REPORT_SIZE];
+    uint8_t raw[KEYBOARD_REPORT_SIZE];
     struct {
         uint8_t mods;
         uint8_t reserved;
-        uint8_t keys[REPORT_KEYS];
+        uint8_t keys[KEYBOARD_REPORT_KEYS];
     };
 #ifdef NKRO_ENABLE
     struct {
         uint8_t mods;
-        uint8_t bits[REPORT_BITS];
+        uint8_t bits[KEYBOARD_REPORT_BITS];
     } nkro;
 #endif
 } __attribute__ ((packed)) report_keyboard_t;
diff --git a/common/wait.h b/common/wait.h
new file mode 100644
index 00000000..40d00b0c
--- /dev/null
+++ b/common/wait.h
@@ -0,0 +1,20 @@
+#ifndef WAIT_H
+#define WAIT_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#if defined(__AVR__)
+#   include <util/delay.h>
+#   define wait_ms(ms)  _delay_ms(ms)
+#   define wait_us(us)  _delay_us(us)
+#elif defined(__arm__)
+#   include "wait_api.h"
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif